Methods and Apparatus to Dynamically Insert Prefetch Instructions Based on Compiler and Garbage Collector Analysis

1. A method comprising: receiving one or more batches of samples associated with cache misses from a performance monitoring unit in a processor system; selecting one or more samples from the one or more batches of samples based on delinquent information; generating a performance impact indicator associated with the one or more samples; determining whether to initiate a delinquent path identification analysis based on the performance impact indicator; when the delinquent path identification analysis is initiated, determining whether the cache misses are in a delinquent region; when the cache misses are in the delinquent region, initiating a garbage collector analysis to attempt to identify one or more delinquent paths; when the cache misses are not in the delinquent region, initiating a compiler analysis to attempt identify one or more delinquent paths; and identifying one or more prefetch points to insert prefetch instructions based on one of the garbage collector analysis and the compiler analysis.

2. A method as defined in claim 1 , wherein the delinquent information comprises at least one of a delinquent region, a delinquent object, a delinquent load, and a delinquent thread.

3. A method as defined in claim 1 , wherein initiating the garbage collector analysis comprises causing a garbage collector to attempt to identify the one or more delinquent paths and one or more deltas associated with one or more delinquent regions.

4. A method as defined in claim 1 , wherein identifying the one or more prefetch points comprises generating a global confidence estimator associated with the one or more prefetch points.

5. A method as defined in claim 1 , wherein identifying the one or more prefetch points comprises confirming the one or more delinquent paths.

6. A method as defined in claim 1 further comprising selecting a sampling rate for receiving the one or more batches of samples from the performance monitoring unit.

7. A machine readable medium storing instructions, which when executed, cause a machine to: receive one or more batches of samples associated with cache misses from a performance monitoring unit in a processor system; select one or more samples from the one or more batches of samples based on delinquent information; generate a performance impact indicator associated with the one or more samples; identify to the performance monitoring unit a sampling rate for receiving the one or more batches of samples; initiate at least one of a garbage collector analysis and a compiler analysis to identify one or more delinquent paths; and identify one or more prefetch points to insert prefetch instructions based on the at least one of the garbage collector analysis and the compiler analysis.

8. A machine readable medium as defined in claim 7 , wherein the delinquent information comprises at least one of a delinquent region, a delinquent object, a delinquent load, and a delinquent thread.

9. A machine readable medium as defined in claim 7 , wherein, if the cache misses are in a delinquent region, the instructions, when executed, cause the machine to initiate the garbage collector analysis by initiating a garbage collector to attempt to identify one or more delinquent paths and deltas.

10. A machine readable medium as defined in claim 7 , wherein, if the cache misses are not in a delinquent region, the instructions, when executed, cause the machine to initiate the by causing a compiler to attempt to identify one or more delinquent paths.

11. A machine readable medium as defined in claim 7 , wherein the instructions, when executed, cause the machine to identify the one or more prefetch points to insert the prefetch instructions by generating a global confidence estimator associated with the one or more prefetch points.

12. A machine readable medium as defined in claim 7 , wherein the instructions, when executed, cause the machine to identify the one or more prefetch points to insert the prefetch instructions by confirming the one or more delinquent paths.

13. A machine readable medium as defined in claim 7 , wherein the machine readable medium comprises at least one of a programmable gate array, an application specific integrated circuit, erasable programmable read only memory, read only memory, random access memory, a magnetic medium, and an optical medium.